不同渥堆发酵方法对普洱茶品质的影响

目的 研究不同渥堆发酵方法对普洱茶品质的影响。方法 以三级晒青茶为原料,分别以高效液相色谱法(high performance liquid chromatography,HPLC)、气相色谱-质谱法(gas chromatography-mass spectrometry,GC-MS)、电子鼻结合感官审评方法对比数控渥堆发酵及传统渥堆发酵对普洱茶品质的影响。结果 主成分分析(principal component analysis,PCA)及聚类分析结果表明,两种渥堆发酵出堆样的香气有差异,但差异不明显。传感器区别贡献率分析(Loading)结果表明,甲基类(W1S)、硫化物类(W1W)对香气测定的贡献率最大,且对数控渥堆发酵出堆的贡献率大于传统渥堆发酵;GC-MS结果表明数控渥堆发酵出堆样的甲氧基类含量高于传统渥堆发酵,进一步佐证了感官审评中数控渥堆发酵出堆样陈香更浓郁。聚类分析和感官审评结果表明,数控渥堆发酵更利于品质稳定的普洱茶的形成。HPLC结果表明,两种渥堆发酵方式的化学物质变化规律基本相同,但数控渥堆发酵出堆样的氨基酸、茶多酚、水浸出物及没食子酸含量显著低于传统渥堆发酵(...

Effects of different pile-fermentation methods on the quality of Pu-erh tea

Objective To provide a theoretical basis for the pile-fermentation of Pu-erh tea, study the effect of different pile-fermentation methods on the quality of Pu-erh tea. Methods using the three-level sun-dried green tea as raw material, HPLC (High Performance Liquid Chromatography), GC-MS (Chromatography-Mass Spectrometry), and Electronic Nose combined with Sensory Evaluation were used to compare and study the NC pile-fermentation and Traditional pile-fermentation on the quality of Pu-erh tea. Results PCA (principal component analysis) and cluster analysis showed that there were differences in the aroma of the two kinds of fermentation piles, but the differences were not significant, Loading (sensor difference contribution analysis) analysis showed that the aroma of piles produced by traditional pile-fermentation, contribution rate of methyls (W1S) and sulfides (W1W) was less than NC pile-fermentation. GC-MS analysis showed that the methyls content of the NC pile-fermentation pile sample was higher than that of the traditional pile-fermentation, and methoxy compounds played an important role in the aging flavor substances of Pu-erh tea, which further supported the stronger aging aroma of the NC pile-fermentation sample in the sensory evaluation. GC-MS cluster analysis and Sensory Evaluation showed that NC pie-fermentation process was more conducive to the formation of Pu-erh tea with stable quality.. HPLC showed that in the two pile-fermentation methods, amino acids, tea polyphenols, water extracts, caffeine and gallic acid in the piles produced by NC pile-fermentation were lower than those of traditional pile-fermentation, but there were no significant differences in catechin and caffeine (P>0.05), and the rest of the contents were significantly different (P<0.05), further supporting the sensory evaluation The taste of traditional fermentation was mellower than that of CNC fermentation. Conclusion NC pile-fermentation can process dozens of kilograms to several tons of tea, with a shorter processing cycle and the stability of quality change during fermentation is better than traditional pile-fermentation, traditional fermentation taste than NC fermentation taste mellow and has higher chemical content than NC fermentation, but continue to explore the parameters of NC fermentation technology settings, can make up for this shortcoming.